具有α-葡萄糖苷酶和二肽基肽酶Ⅳ抑制作用降糖益生菌的筛选

Screening for Potential Novel Probiotic Lactobacillus Strains with High Dipeptidyl Peptidase Ⅳ and α-Glucosidase Inhibitory Activity

以实验室保藏的13株乳酸杆菌为研究对象,研究其细胞代谢物(cell-free,excretory,supernatants,CFS)和细胞内容物(cell-free,extracts,CFE)对α-葡萄糖苷酶和二肽基肽酶Ⅳ(dipeptidyl peptidase Ⅳ,DPP-Ⅳ)的抑制活性;然后对酶抑制率较高的菌株进行益生特性评价,以期筛选出具有潜在降糖作用的益生菌。结果表明,13株乳酸杆菌的CFS对α-葡萄糖苷酶具有一定的抑制作用,抑制率为0%~12.13%;CFE对α-葡萄糖苷酶无抑制作用。13株乳酸杆菌CFS和CFE对DPP-Ⅳ均表现出一定的抑制作用,抑制率分别为0%~7.13%和0%~55.42%。选取酶抑制率较高的嗜酸乳杆菌KLDS1.1003、KLDS1.0901和KLDS1.0902进行益生特性的研究。其中嗜酸乳杆菌KLDS1.0901表现出较高的酸耐受性,嗜酸乳杆菌KLDS1.1003表现出较高的胆盐耐受性和疏水性。主成分分析表明嗜酸乳杆菌KLDS1.1003的综合性能最佳:其对α-葡萄糖苷酶的抑制活性可达10.29%;对DPP-Ⅳ的抑制率为CFS,7.13%,CFE,50.14%;于pH,2.0的条件下孵育1,h后,存活率达到51.55%;在0.3%的胆盐条件下孵育,滞后时间为2.26,h;在二甲苯、乙酸乙酯和氯仿溶剂中的疏水率分别为134.33%、20.51%和344.08%,总体上嗜酸乳杆菌KLDS1.1003具有较高的酶抑制活性和良好的益生特性。

In this study, the cell-free excretory supernatants(CFS) and cell-free extracts(CFE) of 13 Lactobacillus strains deposited in the laboratory were evaluated for α-glucosidase and dipeptidyl peptidase Ⅳ inhibitory activities. Then probiotic characteristics of the strains with higher enzyme inhibitory activities were assessed. The results showed that the CFS of the 13 strains had different α-glucosidase inhibitory activities, with inhibition rates of 0%–12.13%, while none of the CFE possessed α-glucosidase inhibitory activities. The inhibition rates of DPP-Ⅳ with the CFS and CFE of all strains were 0%–7.13% and 0%–55.42%, respectively. L. acidophilus KLDS1.1003, KLDS1.0901 and KLDS1.0902, with higher enzyme inhibitory activities, were selected to determine their probiotic properties. Among them, L. acidophilus KLDS1.0901 showed the highest acid tolerance, and L. acidophilus KLDS1.1003 showed the highest bile salt tolerance and hydrophobicity. Principal component analysis(PCA) showed that L. acidophilus KLDS1.1003 had the best comprehensive performance: its α-glucosidase inhibitory activity was 10.29%;DPP-Ⅳ inhibitory activity was 7.13% and 50.14% for its CFS and CFE, respectively;the survival rate was 51.55% after incubation for 1 h at pH 2.0;under 0.3% bile salt conditions, the lag time was 2.26 h;the hydrophobicity rates in xylene, ethyl acetate and chloroform were 134.33%, 20.51% and 344.08% respectively. Overall, L. acidophilus KLDS1.1003 had high enzyme inhibitory activity and good probiotic properties.